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,G.E. WHITEHEAD.

MIGROMETER GAGE.

No. 375,688. Patented Dec. 27, 1887.

UNITED STATES PATENT OFFICE GEORGE E. \VHITEHEAD, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO THE ItIIODE ISLAND TOOL COMPANY, OF SAME PLACE.

MlCROMETER-GAGEL :SPECIPICATION forming part of Letters Patent No. 375,688, dated December 27, 1857.

Application filed October 1?, 1887. Serial No. 252,136. (No model.)

To all whom it may concern: My invention consists in providing the an- Beitknown that I, GEORGE E. WHITEHEAD, vil 6 with the removable bed 7, which is formed of Providence, in the county of Providence with the notched or countersunk face 8, at the and State of Rhode Island, have invented cerbase of which is formed the slot 9, for catch- 5 tain new and useful Improvements in Microming the dirt from thenotch. The bed 7 is pro etcr-Gagcs, of which the following is a full, vided with the stem 10, which is removably clear, and exact description, reference being and securely inserted in the axial bore 11 of had to the accompanying drawings, forming the anvil, and the bed may be removed from part of this specification. the anvil by pushing upon the end of the stem 13 This invention relates to what is known as 10 through the open end of the bore 11. I a micrometer gage or caliper, which is a defurther provide the micrometer-screw 5 with vice for making fine and accurate measuretheoonical-shapedendpiece orjaw, 12, formed ments. with the smooth shank 13, which is detachably The object of my invention is to provide a mounted on the screw by driving the shank 1 micrometer-gage which will be especially into the socket 16 in the screw, as clearly adapted to measure the diameters of screwsshown in Fig. 2. that is, the diameter of the screw-shank plus Different sized beds 7 and end pieces or the height of the screw-thread or volute. tips, 12, are to be used for the different sizes To the aforesaid purpose my invention conot' screws, the angles of the bed and co-oper- 1o sists, essentially, in the combination, in a miating tip being adapted to the angle of the crometengagc, of a countersunk or notched screw-thread. \Vhen the tip 12 is seated in bed on the anvil with the projecting or taperthe notch of the bed, the gage will read zero. ing end piece on the cooperating micrometer- In order to measure the diameter of ascrew, screw, and, further, of other details of conas 14, the screw is placed in the gage with the 7 25 struction, all as hereinafter fully described thread 15 thereof seated in the notch or fork and claimed. 8 of the bed, then the micrometer-screw 5 is In order that my invention may be fully screwed down until the conical end 12 takes understood, I have illustrated in the accomsnugly in between the threads 15, and this panying drawings, and will proceed to de reading will give the true diameter of the 3o scribe the best form thereof so far devised by screw, the diameter being the diameter of the me, with the knowledge that such form may screw-shank plus the height of the thread.

be variously modified without, however, mak- In cutting screws I am at all times enabled ing a substantial departure from the spirit of to quickly ascertain the trueness ofthe die by the invention. gaging the screw cut thereby and comparing 5 In the accompanying drawings, Figure lis the reading with the known reading of the a broad side view of my improved micromestandard screw. tengagc; and Fig. 2 is a view of the same, It is to be observed that my invention contaken at right angles thereto. Fig. 3 is an entemplates the making of the anvil in one piece larged longitudinal sectional view of the gage having a recessed or countersunk face, and 0 0 with the micrometer-screw broken off and a therefore the claim for a countersunk bed coportion of a screw mounted in the gage for operating with the micrometer-screw commeasurement. prises such construction.

In the said drawings like numbers desig- Having thus described my invention, Iclaim n ate corresponding parts throughout. as new and desire to secure by Letters Patent-- 5 5 Referring to the drawings, the number 4 1. In a micrometer-gage, the anvil thereof designates the frame of the gage or caliper, at formed with a countersunk face to receive the one end of which is mounted the ordinary miscrew-thread,and themicrometer-screw formed crometer-screw, 5, which is designed to co-opwith a projecting face to take in between the erate with the ordinary adjustable anvil, 6, screw-threads, as and for the purpose herein 50 situated in the other arm of the frame oppodescribed.

site the screw 5. 2. The combination,ashereinbeforeset forth,

with the gage provided with an anvil having micrometer-screw 5, provided with the conia detachable bed formed with a countersunk cal or tapering end piece, 12, removably secured face to receivethescrew-thread, of the micronito the screw, and the adjustable anvil 6, pr0- 15 eter-screw provided with a detachable end vided with the removable bed 7, formed with piece having a conical face, substantially as 3 the notch 8, substantially as described. described. 5. In a micrometergage, the bed 7, formed 3. In a micrometer-gage, the notched or with the notch or recess 8, and the slot 9, as

countersunk bed to receive the screw thread described. and the taper end to take in between the dia- GEORGE E. VVHITEHEAD. metrically-opposite threads of the screw, as \Vitnesses: described. J. A. MILLER, Jr.,

frame 4, of the M. F. BLIGH.

4. The combination, with the 

